人类精子基因组。通过DNA重缔合动力学进行分析。

The human spermatozoa genome. Analysis by DNA reassociation kinetics.

作者信息

Hernández O, de Los Angeles Bello M, Rosado A

出版信息

Biochim Biophys Acta. 1978 Dec 21;521(2):557-65.

Abstract

The physicochemical characteristics of the human spermatozoa DNA have been analyzed by means of analytical ultracentrifugation and reassociation kinetics and compared with DNA from a somatic human cell, the leukocyte. Human spermatozoa DNA is composed of a major (86.7%) and a minor (13.3%) component with buoyant densities in neutral CsCl corresponding to 1.697 and 1.704 g/cm3, respectively. The DNA obtained from leukocytes contained only the first component. Reassociation kinetics of sheared DNA showed that the most rapidly-renatured repeated sequences consituted 12.1% of the sperm genome and only 9.2% of leukocyte genome. On the contrary single copy sequences were more abundant in leukocyte (64%) than in spermatozoa (59%) DNA. Reassociation kinetics with long DNA fragments (2000 nucleotides) were clearly different between sperm and leukocyte DNA, indicating the presence in sperm cells of a specific cluster of highly repetitive DNA. This entity may play a role in giving the spermatozoa nucleus its characteristic properties, involving supercoiling, quasi crystal structure, stability, lack of transcription, etc. and secondarily may function as an early pairing mechanism during syngamy.

摘要

通过分析超速离心和重缔合动力学方法对人类精子DNA的理化特性进行了分析，并与来自人体体细胞白细胞的DNA进行了比较。人类精子DNA由主要成分（86.7%）和次要成分（13.3%）组成，在中性CsCl中的浮力密度分别对应于1.697和1.704 g/cm³。从白细胞中获得的DNA仅包含第一种成分。剪切DNA的重缔合动力学表明，复性最快的重复序列占精子基因组的12.1%，仅占白细胞基因组的9.2%。相反，单拷贝序列在白细胞DNA（64%）中比在精子DNA（59%）中更为丰富。精子和白细胞DNA之间长DNA片段（2000个核苷酸）的重缔合动力学明显不同，表明精子细胞中存在高度重复DNA的特定簇。该实体可能在赋予精子细胞核其特征性质方面发挥作用，涉及超螺旋、准晶体结构、稳定性、缺乏转录等，其次可能在配子融合过程中作为早期配对机制发挥作用。